Natural GMOs Part 83: Natural biology comes with no guarantee of safety

posted in: Syndicated | 23

Scanning electron micrograph of Escherichia coli, grown in culture and adhered to a cover slip:

Image: National Institutes of Health (part of the United States Department of Health and Human Services)/Public domain.

Natural GMOs can be really really bad and fundamentally unsafe, because Nature is not scrutinised by any human regulatory agency, and many natural GMOs get their genes from all over the place. The first investigated example of this over-the-top natural-sexual promiscuity discovered by scientists is natural gene movement to and from the gut bacterium Escherichia coli.

Joshua Lederberg’s 1946 discovery of such genetic behaviour by E. coli was heralded by Salvador Luria as likely to be “among the most fundamental advances in the whole history of bacteriological science”. Over the years we have come to realise that this natural mating behaviour is a natural process for indiscriminant injection of genes into new locations in other organisms.

It is a perfect example of the rule that natural biology comes with no guarantee of safety, and a perfect illustration that gene movement between species is completely natural. Nature simply does not come with a certificate to guarantee “gene contamination will not occur”.

E. coli comes in some varieties of germ that cause disease in humans, and many other varieties that do no harm at all  to humans. The disease causing strains of E. coli can evolve naturally from safe ones by processes of gene-swapping. One form of gene swapping that they us  is called conjugation (mating), and some E.coli can conjugate with almost anything. That’s what they do naturally. The biological details of conjugation are well explained by a new Guardian newspaper blog posting:

Food poisoning reminds us that bacteria do have sex | GrrlScientist | Science |
Through the wonders of bacterial conjugation, formerly friendly gut bacteria have been transformed into merciless killers lurking in your salad bowl.
Those of you who live in Germany, as I do, are probably concerned about the recent and ongoing E coli outbreak that has killed 10 people (so far) and sickened more than 1000. The news coverage provides updates on the whos, whats, wheres and whys of this outbreak, but discussions of how such events occur are lacking or incomplete, so I thought I’d fill you in.
Contrary to what you might think after seeing most news reports, not all E coli (shortened from their scientific name, Escherichia coli) are toxic: in fact, most strains are beneficial to their hosts. E coli are normal gut flora whose preferred habitat is the large intestine. They are protective because shortly after a baby is born, E coli become established in the gut, crowding out disease-causing pathogenic bacteria by filling up all available space with their sheer numbers. E coli are also beneficial; producing vitamin K2, which has a variety of functions in the body.

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David Tribe is an applied geneticist, teaching graduate/undergrad courses in food science, food safety, biotechnology and microbiology at the University of Melbourne.