From KurzweilAI:
Duke University researchers have engineered microbes as “swarmbots” designed to only survive in a crowd. The system could be used as a safeguard to stop genetically modified organisms (created with tools such as CRISPR) from escaping into the surrounding environment.
Collective survival
“Other labs have addressed this issue by making cells rely on unnatural amino acids for survival or by introducing a ‘kill switch’ that is activated by some chemical,” said Lingchong You, the Paul Ruffin Scarborough Associate Professor of Engineering at Duke University. “Ours is the first example that uses collective survival as a way of intrinsically realizing this safeguard.* “In general, this concept does not depend on the use of antibiotics,” said You. “We’re using non-pathogenic E. coli, but we hope to demonstrate that the same concept can be established with a probiotic strain of bacteria.” Another method would be to insert a contained population of bacteria that could help the body respond to intruders. “This is the foundation,” said You. “Once we’ve established the platform, then we have the freedom to introduce whatever proteins we choose and allow these cells to engage in many different applications.” The approach could also be used to reliably program colonies of bacteria to respond to changes in their surrounding environment, such as releasing specific molecules on cue.
More here.