Today's Topics in AgBioView.
* Rick Roush on Australian Genethics' Warning about Bt and Anthrax
* Tom DeGregori on Manufacturers of Bt products
* David Tribe on Natural Terrors
* Red Flag for Green Spray
* Friend or Foe?
* Christoph Reuss' Worries about Bioweapons, Calls for Banning All Biotech
* Rick Roush and Prakash Reply
From: Rick Roush
Subject: Re: Australia: Warning about Bt and Anthrax
I replied to Bob Phelps directly about his emails to Australian politicians (See Below). He has not responded to the clarification on facts and interpretation.
Bt crops use only a few of the insect specific proteins but nothing from the plasmids (or genes) that give anthrax its killer potential. The genes used for insect control and those that cause anthrax are well known and not confused in either plants or Bt sprays. The anthrax toxin has three components. One of them, called edema factor (EF), prevents cells called macrophages from gobbling up bacteria. Another, called lethal factor (LF), kills the macrophages and eventually the host, too. The third component, protective antigen or PA, helps shuttle the other two into macrophages (Martin Enserink, Science, October 19, 2001)
As Mary-Howell & Klaas Martens implied in their email to AgBio, commercial Bt formulations are prepared under tight quality control, and to the best of my knowledge, have never been associated with any hazards more serious than allergies that could arise from the wide range of bacterial proteins in Bt sprays. We shouldn't encourage fear of Bt sprays from reputable companies. Still, Bt crops haven't even been correlated with allergies, and eliminate even the very low potential for accidental contamination with anthrax toxins or bacteria that could occur in Bt sprays. To argue that trangenic crops cause any sort of risk related to anthrax is about like claiming that tomatoes are risky because they are closely related to deadly nightshades.
Also, Starlink corn has not been registered because it could not be proven that it wasn't a human allergen, not because it was a "probable" human allergen.
In reply to questions from Mary-Howell & Klaas Martens , many organic growers are surprised to learn that many currently used strains of Bt are GM. M-Trak (where the Bt strain is now accepted as a result of a court case to be "tenebrionis", not "san diego") is a beetle active Cry3A Bt toxin produced by transformed Pseudomonas flourescens, which are then killed to produce a "CellCap" system where the cell wall is supposed to help protect the toxin from degradation and give greater field persistence. This was registered in 1991 and because the bacteria were dead, easily cleared the regulatory system. Another is MVP; same system but used the caterpillar active cry1A gene.
Often times, Bt strains are too specific for some commercial interests, so researchers have combined toxins through conjugation. A plasmid bearing the cry3A gene from strain tenebrionis was transferred to a caterpillar active Bt kurstaki with cry 1A to produce a transconjugant which has activity against both some beetles and many caterpillars. It was called Foil, and is supposed to be particularly useful in potatoes for control of both Colorado potato beetles and European corn borers. Because this was done by genetic manipulation rather than genetic engineering, it was approved for use by US EPA in 1990. I don't know the specifics about Agree, but I assume that the same process has been used.
I can't answer your specific questions about breakdown between organics and conventional farms, and would be surprised if Dupont, Ecogen, Mycogen, Sandoz, Abbott and Certis have the answers in that detail (they could probably tell you crops and regions, but not how much was organic). However, about ten years ago, half of all Bt use was on forestry in Canada, and I suspect that is probably still about right. Much or most of the rest goes onto crucifer crops (cabbages, broccoli, etc), most of which would not be organic. Some of the remainder is used on conventional and organic grapes and tomatoes.
To: All Victorian MPs; other MPs as addressed
URGENT: Need strong GE laws based on precaution and real evidence!!
From: Bob Phelps, Director GeneEthics Network
'Bt GM crop toxin is from Anthrax family'
The Bt gene (from the soil microbe Bacillus thuringiensis) which produces an insect toxin is now genetically engineered into many food crop plants (including 30% of the Australian cotton crop from which oil, seed and linters are derived).
Starlink corn has not been registered as human food because it is one new variety of Bt that is recognised as a probable human allergen. Many other strains of Bt have been approved for inclusion in our food supply, despite a paucity of sound evidence showing their safety. This is relevant in the current public concerns over Anthrax as Bt is a member of the same family of micro-organisms.
We again invite you to delay passage of the Gene Technology Act 2001 until the state government conducts a public review of needed amendments. We fully support the regulation of gene technology and its products but the proposed system is manifestly inadequate. Our letter to Health Minister Thwaites, previously sent to you, sets out our concerns.
We ask you to strengthen the Bill's provisions, to make it strictly evidence based, which the new Office of Gene Technology Regulator and its processes are not. Please favourably consider our request after reading the following.
From: Tom DeGregori
Subject: Manufacturers of Bt products
Many thanks to Mary-Howell & Klaas Martens for their interesting and informative posting of Bt products, who manufactures them and who uses them. Unfortunately, their posting came with a raft of ideological baggage. For the past few years since the introduction of Bt corn and the attack against it by the anti-biotech crowd, we have been bombarded with propaganda about the possibility that the extended use of Bt corn would lead to rapid developement of insects resistant to the toxins of the live Bt used in "organic agriculture" by those virtuous, environment loving, children protecting "organic" farmers. No mention was made to my knowledge in any of these arguments that conventional farmers were using this "environmentally friendly" form of pest control. Isn't it interesting that we suddenly are made aware of the fact that convential farmers use live Bt when the anthrax issue arises and there is some possibility, however remote - and I stress as I have repeatedly done, that it is extremely remote - that we l
It is also important to note the difference in the tenor of the postings. In my recent book and my posting where I discuss the issue of live Bt's use and the fact that many scientist consider that Bt is part of the same species as B. Anthracis, I clearly state that the danger is remote but nevertheless greater than any possible danger from Bt corn. If Mary-Howell & Klaas Martens care to read the AgBioView postings, it should be clear to them that it was the anti-biotech propagandists who have been trying to use the Anthrax scare to frighten people further about Bt corn in what has to be perverse and perverted "logic" that reflects a lack of intellectual integrity even for the groups that are promoting this line. Craig Sams uses this type of argument repeatedly - pesticides are dangerous and we don't use them, well we do but they are not hamful because they are "all natural" and others use them, well they may be harmful but we don't use very much of them and others use more of them and anyway we are phasing
Simply stated, when using live Bt is virtuous, it is "organic," when one can use perverted language and scare tactics to make it dangerous or possibly so, then it is largely use in conventional agriculture. Of course, we are to believe that a plant that produces a protein that is completely broken down in the stomach is an anthrax threat though there are no genes in the plant that code for the anthrax toxins but that a live Bacillus with the genes that do code for the anthrax toxin is purely harmless. But, if the live Bt is harmful, it is because more of it is used in conventional agriculture. How a rational person could reach such an extraordinary conclusion is simply beyond all belief. In other words, whatever is good in the world, is "organic" and whatever is harmful is done by someone else. Magic anyone?
- Tom DeGregori
P.S. - For the record Bt resistant diamondback moths were identified and discussed in peer reviewed journal articles prior to, repeat prior to the introduction of Bt corn. Modern agronomy and biotechnology have a variety of strategies to overcome the development of resistant insects; "organic" agriculture can only complain of the threat to them by others using "their" product.
Question - recently, there was a posting (I would appreciate having it re-posted) indicating that it was possible to knock out the genes that code for Bt's harmful endotoxins but that the "organic" enthusiasts oppose it because of the inherent evil of bioengineering of life forms. Have any of the impressive list of firms that produce live Bt considered knocking out these genes producing an even safer live Bt for use by those farmers whose thought processes have not been degraded by ideology? I would also be interested in what Mary-Howell & Klaas Martens would think of this and whether they would advocate the use of genetically engineered Bt? It also should be noted that the Bt that has been in use for some time is itself the product of the genetic manipulation of the time of its early use and is not a pure product of "nature." - TRD
>Subject: Manufacturers of Bt products
>From: "Mary-Howell & Klaas Martens"
From: David Tribe
Posted: To the Anti-Biotech Activist Newsgroup
...However, Bacillus expert Lars Andrup of the National Institute of Occupational Health in Copenhagen has identified a novel gene-swapping system that enables Bt to exchange an unusually wide variety of DNA with other Bacillus cells. The potential for spawning very dangerous strains and unleashing them into the environment is clearly there, he says."
- New Scientist, October 9, 1999
"B.t. belongs to a small group of closely related Bacillus species, including B. cereus, a bacteria that is an agent of food poisoning, and B. anthracis, the pathogen of the virulent animal disease, anthrax. These three bacteria are so similar it has been theorized that they are all varieties of the same species. If B. cereus is cultured with B.t. cells, genetic material is transferred to the B. cereus cells that allows B. cereus to produce B.t.'s crystal proteins. Transfers of genetic material between B. anthracis and B.t. have also occurred." .....
>SHOCK, HORROR, Dangerous strains of bacteria can be created naturally in nature,
> giving rise to disease, and there are no natural barriers that regulate this gene movement.
Wait a minute, I thought the reason many people believe that scientists doing GE experiments are dangerous is that they are doing things nature doesn't do. But here we have evidence that "nature's genetics", or naturally promiscuous gene swapping between B. anthracis (Anthrax) and B. cereus and B. thuringiensis (Bt) is dangerous too.
Scientists aren't the only source of unleased new strains - nature is, and what's more is not regulated or overseen by human committees, anything goes!
All this seems to indicate that some fundamental assumptions about the supposed safety of natural agents, and the feeling that there is some OBLIGATORY natural harmony of pristine nature are simply hogwash.
- David Tribe Ph.D., Microbiology and Immunology, University of Melbourne
Subject: Re: Anthrax
>Alice Webster Wrote Re statement by Bob Phelps that anthrax and the Bt bacteria are related:
>Wow! Scary stuff
>Does this mean that we should stop using Bt spray? Alice
>Organic Issues (firstname.lastname@example.org) Posted: 10/19/2001 By email@example.com
>Bt GM crop toxin is from Anthrax family
Here's one extra reference showing how the use of live Bt bacteria may constitute a health hazard.
Of course if the use of live Bt in organic farming causes any deaths they and other organics groups will be legally liable, given that this scientific information is now common public knowledge, and that they are now well aware and formally advised of this hazard because of this correspondence. Of course I imagine such legal liability may be mitigated if they include health warnings on their produce. Its really good that Bob Phelps bought this issue to our attention.
- Regards, Dave Tribe
Red Flag for Green Spray
- Debora Mackenzie, New Scientist, 29 May 1999
Bacterial spores sprayed on organic crops as a pesticide may damage the health of people who inadvertently breathe them in. French researchers have found that inhaling the spores can cause lung inflammation, internal bleeding and death in laboratory mice. Bacillus thuringiensis, or Bt, produces a toxin that kills insects. The dried spores of the bacteria have been used as a pesticide for more than 30 years and are one of the very few insecticides sanctioned for use on organic crops in Europe. Bt is also widely used to combat pest such as the spruce budworm, a caterpillar that attacks trees. Last year, French scientists isolated a strain of Bt that destroyed tissue in the wounds of a French soldier in Bosnia. The strain, known as H34, also infected wounds in immunosuppressed mice (This Week, 30 May 1998, p7).
Now the same team has found that H34 can kill mice with intact immune systems if they inhale the spores. FranEoise Ramisse of le Bouchet army research laboratories near Paris and her colleagues found that healthy mice inhaling 108 spores of Bt H34 died within eight hours from internal bleeding and tissue damage. Spores from mutants of the same strain which did not produce the insecticide were equally lethal to mice, suggesting that it was not to blame. Ramisse a her colleagues presented their results at a conference in Paris last month. The researchers think that the symptoms are caused by other toxins. The bacterium's close cousin, Bacillus cereus, produces a toxin that ruptures cell membranes. And in 1991, Japanese researchers showed that B. thuringiensis produces the same toxin. In fact, when the French researchers ran samples from the soldier from Bosnia through an automated medical analyser, it seemed to show that the bacterium was B. cereus.
Ramisse suggest that companies producing Bt spores might make them safer by deleting the promoter sequence that activates the gene for the membrane-rupturing toxin.
Although H34 is not used as a pesticide, commercial strains of Bt tested by the researchers also killed some mice or caused lung inflammation when inhaled. The team obtained these strains from Abbott Laboratories, a major supplier of Bt based in Chicago. Ramisse points out that the strains are sprayed on forest pests at concentrations of 1011 spores per square metre--and so might pose a danger to people in the immediate vicinity.
But Abbott maintains that Bt is safe. "We stand by our products," says Linda Gretton, a company spokeswoman. The French researchers have not yet tested strains made by other companies.
"I suspect Bt infection is more widespread than we realise," says Ramisse.
Recorded infections by Bacillus pathogens are comparatively rare. Known pathogenic species can have very distinctive symptoms. Anthrax, for instance, is caused by B. anthracis. But where such tell-tale signs are absent, Ramisse suspects that doctors often fail to recognise that the bacteria are responsible, dismissing any Bacillus in patients' cultures as contamination. Consequently, the cultures are often discarded. "I wish they would start keeping them so we could check for Bt," she says. When Bt was sprayed in towns in Oregon in 1991 to combat gypsy moths, the bacterium was found in clinical samples from 55 patients who had been admitted to hospital for a variety of other reasons. Robert Haward of the Soil Association, which represents Britain's organic farmers, says that they may have to use masks and take more care when spraying the spores on crops.
Friend or Foe?
- Debora MacKenzie, New Scientist, October 9, 1999
The bacteria Bacillus thuringiensis (Bt), B. cereus and B. anthracis are all the same species, biologists believe. If, the story asks, you're thinking "so what?", then consider this: Bt is sprayed over crops in vast quantities and B. anthracis is the bug that causes anthrax.
Small genetic differences have so far maintained the distinction that makes B. anthracis a notorious human pathogen and Bt merely a useful pest control bug. However, Bacillus expert Lars Andrup of the National Institute of Occupational Health in Copenhagen has identified a novel gene-swapping system that enables Bt to exchange an unusually wide variety of DNA with other Bacillus cells. The potential for spawning very dangerous strains and unleashing them into the environment is clearly there, he says.
So why use Bt at all? For one thing, it is a highly successfully pesticide. Bt makes a toxin that kills insects but hurts nothing else. Genes for the toxin have been engineered into crops, but most farmers, timber growers and gardeners get it from live bacteria. More than 500 tonnes--five billion billion bacteria--are sprayed annually in the US alone. Similar amounts are sprayed in Europe. It is the only designated insecticide permitted on organic produce in Britain.
If outbreaks of anthrax had been traceable to cabbage patches we would have, the story says, known about them. But before you consider the anthrax link, some claim that Bt even in its familiar form may not be as benign as we like to think. A closer look at its genes shows it is remarkably similar to B. cereus, an organism which causes about four serious outbreaks of food poisoning a year in the US. The only difference between them is a few plasmids. And it now appears that Bt is well equipped for swapping these small DNA loops with other bacilli. The surprising but generally held view of Bacillus specialists who met in New Mexico in August is that, the story says, plasmids aside, Bt, B. cereus and B. anthracis are one species. Take away its insect-killing plasmid, for example, and "Bt cannot be distinguished from B. cereus," says microbiologist Anne-Brit Kolsto of the University of Oslo. "All three are one species based on genetic evidence." Paul Jackson of Los Alamos National Laboratory, New Mexico, says s
Bt, B. cereus and B. anthracis were considered different species because they favour different hosts and carry different plasmids. Two plasmids in B. anthracis code for toxins that cause anthrax in mammals. Bt has one that makes insect poisons. And although its plasmids seem innocuous, the main part of Bt's genetic material codes for toxins that can cause diarrhoea, vomiting, muscle and kidney damage and liver failure.
But recent research in Canada suggests that commercial strains of Bt do make B. cereus toxins. Vern Seligy and colleagues at the Canadian federal health ministry told the American Society for Microbiology in Chicago in June that, at concentrations similar to those in aerial sprays, two commercial strains of Bt killed human cells in culture, by producing toxins that behaved like those from B. cereus. "The DNA sequence information for most of the virulence genes in B. cereus is in current Bt products," says Seligy. There are also reports of health damage with Bt. Katy Young of the Environmental Health Alliance, a campaigning group in British Columbia, says that in 1994, after Bt was sprayed to kill gypsy moths in forests near Victoria, 62 people had problems consistent with B. cereus toxins. Their symptoms included diarrhoea, vomiting and respiratory problems. Young suspects many infections are never diagnosed.
While agreeing that Bt produces small amounts of cereus toxins, the US Environmental Protection Agency (EPA) says there is no valid evidence to link use of Bt insecticides with episodes of diarrhoea, and it has therefore declared the products safe. Some scientists, however, point out that commercial Bt strains could become more aggressive, perhaps by swapping regulator genes with wild B. cereus. Andrup has discovered that some strains of Bt, very similar to those used commmercially, contain plasmids that cause the bacteria to join up with other Bacillus bacteria, and pass DNA back and forth (Journal of Bacteriology, vol 181, p 3193).
"This powerful conjugation system," says Andrup, "could spawn harmful bacteria in the environment, where sprayed Bt can survive a year." Not least, Bt could pass on the gene-swapping mechanism itself. The dangerous plasmids in B. anthracis appear unable to pass into other Bacillus species. But armed with powerful new conjugation genes from Bt, in theory, this could change.
It's an alarming scenario. However, Jackson thinks it is unlikely to happen because the bacilli rarely meet in the vegetative or "growing" state needed for plasmids to be swapped. Bt usually grows only in its insect host, B. cereus in soil, B. anthracis in mammals. This makes it extremely unlikely that Bt will ever swap dangerous DNA with its Bacillus cousins, says Jackson.
Others are not reassured, however. While separate territories keep the bacteria apart in nature, they fear modern agriculture might bring the different species together. Artificially growing and spreading billions of extra Bt in sprays might cause events that are vanishingly rare in nature to occur often enough to spawn dangerous hybrids, says Andrup. "We should certainly remove the conjugation system from commercial strains," he says.
From: firstname.lastname@example.org (Christoph Reuss)
Subject: Re: reply to Hawking
Prakash wrote to Hawking:
> I read your comments from a 'Reuters' report on bioterrorism and the need
> to reach out to the stars. You are somewhat justified in your fear of
> misuse of 'Genetic Engineering' as a weapon by the terrorists but in
> reality these evil people are employing the simple 19th century
> microbiology to spread this terror right now. As you well know, one does
> not need a sophisticated genetic engineering to develop deadly microbes
> that can simply be isolated in nature and cultured.
As Prakash says: "right now". And right now, the stuff is pretty ineffective. But what if they'll use much more effective GE bioweapons in the future? Hawking is right: GE is gambling with our future, and that's why we should ban it altogether unless we can find new planets to afford dumping the old one (and even then, GE would be dangerous, as it can spread thru starships too).
From: "C. S. Prakash"
Subject: Re: Fwd: Re: reply to Hawking
Dear Mr. Reuss:
Surely, biotech is a potent tool to make bioterrorism more effective in the hands of evil people. But it is not a reason to ban this technology as this is our greatest hope to develop improved tools to detect the germs, develop better vaccines to protect us against future attacks and also to invent better antibiotics to treat any problem. If you ban it, the law abiding citizens and institutions would stop using the technology but would not prevent terrorists and rogue nations to pursue it. This would make the world even more vulnerable to greater harm and would leave us more helpless.
It is also silly to even think of banning the whole spectrum of technology just because of possible misuse. It is like saying "Let us now stop all commercial aviation or the mail system because these two were employed to perpetrate the recent terrorist attacks." - C. S. Prakash
From: email@example.com (Christoph Reuss)
You argue like the U$ National Rifle Association who claims the country is safest when everyone owns a private gun. As the record shows, this concept fails miserably. With GE weapons it's even worse, because GE is uncontrollable and has an immense potential of harm, so the bad guys are always a step further. Do you really expect that an antidote can be developed ad hoc when unknown GE bioweapons are spreading like wildfire? As usual, you're dreaming in GE wonderland with unrealistic promises.
Your comparison with commercial aviation or the mail system is invalid, because with some decent safety measures, the possible harm that can be done with these systems is very limited. (U$ airport and radar safety *before* 11-Sep was very sloppy -- not anymore!) But this doesn't apply to GE at all. More than nuclear power, GE is uncontrollable and its potential of harm is unlimited.
GE has to be stopped in its tracks, to prevent GE bioweapons from being developed in the first place. Anything that's around will be misused (or get out of control by itself..). If the knowledge is banned too, a total ban can be enforced, even in so-called "rogue nations" (who got their weapons of mass destruction from the West!!).
From: Rick Roush
You wrote that "GE has to be stopped in its tracks.... If the knowledge is banned too, a total ban can be enforced, even in so-called "rogue nations" (who got their weapons of mass destruction from the West!!)."
How can you ban knowledge? Enough was known about genetic engineering of bacteria in the late 1970's and early 1980's that one could even then have mixed traits such as antibiotic resistance and toxins. Stopping GE on things like crops and medicines would be completely irrelevant to preventing bioterror. Such GE uses an almost completely separate range of new (less than 15 year old) techniques and goals than you would use in manipulating micro-organisms to kill people. You might as well propose the banning of further work on physics and mechanical engineering so that bombers couldn't use planes or trucks.
Have you got a way to "mind-wash" all those rogues to make them forget what has been known in most cases for 20 years? Will you also prevent them from doing their own research?
While I am writing to you, I just saw a Time magazine poll where 71% of Americans thought we should use military action to remove Saddam from Iraq (and another 10% weren't sure). Using your often voiced arguments that the people want labelling so we should give it to them, "the people" want the US to attack Iraq, so we should right?
Of course not. Hopefully cooler, more strategic, and more informed heads in the US will prevail against both GM labelling and reckless adventures.
Thank you for your reply. There are no GE bioweapons spreading like wildfire except in your imagination. The anti-biotech groups are simply trying to use the present unfortunate terrorist scenario (which has nothing to do with GE organisms) to advance your cause.
The real bioterror that is killing millions of people around the world every year are cholera, malaria, AIDS, TB and other infectious diseases along with many physiological maladies such as cancer plus those with genetic predisposition such as MS, CF, Alzheimers disease etc. How can you even accuse me of dreaming in 'GE wonderland' when already so many benefits such as new drugs, new screening procedures and vaccines have been developed using biotechnology? You just seem to evade reality. Biotechnology along with modern immunology and other scientific advances are out best hope against both natural bioterror and those produced by evil terrorists.
If you are right in saying that bioweapons are exported from the West (which we are not sure is true), then the same West can develop antidote too. I hope you recognize the flaw in your own reasoning.
So you are confident that with decent safety measures, aviation and mail systems can be made safer but you do not believe that biotechnology can be safer? Biotech is already safe! There has not been one single instance of unintended harm ever from biotechnology (please do not start with L-tryptophan - it's damage was not because of biotech). One must stop saying that "More than nuclear power, GE is uncontrollable and its potential of harm is unlimited." - Such naive assertions would not work in an educated newsgroup like this. Hundreds of thousands of studies have been done in the past thirty years using recombinant DNA. Can you cite one evidence to support your assertion?
In 1890s, luddites waged a war against immunization. Later, a similar campaign was waged against pasteurization of milk. Thank God, both failed. Similarly the current anti-biotechnology war is surely going to fail too as the humanity cannot afford to ignore a potent solution to real problems because of the ideological and irrational fears of a small minority.
You cannot fight progress with orchestrated fears of misuse. While the potential for misuse with any technology is real, that needs to be fought with a different strategy.