Technical Report on Mirror Bacteria: Feasibility and Risks

This report describes the technical feasibility of creating mirror bacteria and the potentially serious and wide-ranging risks that they could pose to humans, other animals, plants, and the environment. It accompanies the Science Policy Forum article titled “Confronting risks of mirror life”, published December 12, 2024. In a mirror bacterium, all of the chiral molecules of existing bacteria—proteins, nucleic acids, and metabolites—are replaced by their mirror images. Mirror bacteria could not evolve from existing life, but their creation will become increasingly feasible as science advances. Interactions between organisms often depend on chirality, and so interactions between natural organisms and mirror bacteria would be profoundly different from those between natural organisms. Most importantly, immune defenses and predation typically rely on interactions between chiral molecules that could often fail to detect or kill mirror bacteria due to their reversed chirality. It therefore appears plausible, even likely, that sufficiently robust mirror bacteria could spread through the environment unchecked by natural biological controls and act as dangerous opportunistic pathogens in an unprecedentedly wide range of other multicellular organisms, including humans. This report draws on expertise from synthetic biology, immunology, ecology, and related fields to provide the first comprehensive assessment of the risks from mirror bacteria. It consists of eight chapters and starts with a general introduction, followed by an examination of the initial creation of mirror bacteria, their further engineering, as well as biosecurity and biosafety implications. The remaining five chapters cover risks to human health, medical countermeasures, risks to other animals, risks to plants, and the potential ecological consequences of their introduction into the environment.