“Mirror bacteria” could pose serious risks to global health

Lab-made ‘mirror bacteria’ could pose an imminent health risk to humanity, scientists warn.

These hypothetical organisms get their name from the way their molecules would be oriented in the opposite direction to those of the cells of all existing life – similar to the mirrored shapes of our left and right hands – and, because of this fundamental strangeness, could be dangerous for humans. , animals and plants.

Synthetic bacteria are currently in the early stages of development and could be more than a decade away, according to an article in the journal Science.

“Our view is that mirror bacteria and other mirror organisms should not be created,” the researchers wrote.

The direction of a molecule, like the proteins in our body, is known as chirality. All DNA and RNA found in all life forms on Earth are made of “right-handed” molecules, while proteins are made almost entirely of “left-handed” amino acids.

The chirality of a molecule can determine its structure and function. For example, the drug thalidomide exists in two different chiralities – known formally as enantiomers – where one is therapeutic for the treatment of morning sickness and the other causes serious birth defects.

According to the new paper, work has begun on building bacteria with mirrored molecules of opposite chirality to all other life forms on Earth, with left-handed DNA and right-handed proteins.

“Driven by curiosity and plausible applications, some researchers have begun work toward creating life forms composed entirely of mirror-image biological molecules,” the researchers wrote. “The ability to create mirror life is likely at least a decade away and would require significant investment and major technical advances.”

According to the new paper, researchers fear that mirror bacteria could evade natural predators such as phage viruses and microscopic protists, or even our body’s immune cells, because they rely on chiral-dependent binding to recognize bacteria.

This could mean that immune defenses may not be as effective against mirror bacteria, leaving animals and plants vulnerable to infection unhindered.

“Our analysis suggests that mirror bacteria would likely evade many immune mechanisms mediated by chiral molecules, potentially causing lethal infection in humans, animals and plants. They would likely escape predation from phages with natural chirality and many other predators, thus facilitating their spread throughout the global environment,” the researchers wrote.

Scientists suggest that, in a worst-case scenario, mirror bacteria could quickly and fatally infect many life forms on our planet.

“We cannot rule out a scenario in which a mirror bacteria would act as an invasive species in many ecosystems, causing widespread fatal infections in a substantial fraction of plant and animal species, including humans. Even a mirror bacteria with a range “Narrower host populations and the ability to invade only a limited set of ecosystems could nevertheless cause unprecedented and irreversible damage,” the researchers write.

The researchers note that although this threat is still distant, it could very well occur in the coming decades. They say that in the coming years, before mirror bacteria develop, we will have to create limits on research on these organisms, or even ban it altogether.

“Unless compelling evidence emerges that mirror life would not pose extraordinary dangers, we believe that mirror bacteria and other mirror organisms, even those with biocontainment measures, should not be created,” the researchers wrote. researchers.

“We therefore recommend that research aimed at creating mirror bacteria should not be permitted and that funders should make it clear that they will not support such work.”

If this research cannot be stopped, scientists suggest developing ways to control and prevent these mirror bacteria from causing harm.

“Such research could include the study of the interaction of mirror biomolecules with the immune system as well as the development of detection methods and biomonitoring systems. Although countermeasures cannot prevent widespread damage, they could offer limited or localized protection,” they said.

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References

Adamala, KP, Agashe, D., Belkaid, Y., De C Bittencourt, DM, Cai, Y., Chang, MW, Chen, IA, Church, GM, Cooper, VS, Davis, MM, Devaraj, NK, Endy , D., Esvelt, KM, Glass, JI, Hand, TW, Inglesby, TV, Isaacs, FJ, James, WG, Jones, JDG, . . . Zuber, M. T. (2024). Facing the risks of mirrored life. Science.