Researchers in San Diego announce a new molecule that stops bacteria from mutating to become resistant to antibiotics.
Microbes have ruled the earth for more than a billion years; comparatively, we humans are just upstarts. Yet since the invention of penicillin in 1940, we have inflicted a crippling blow on many types of bacteria that make us ill or kill us.
But the bugs have struck back by activating DNA that is prone to errors when it replicates. This increases the chance that mutations will develop to fend off the mortal threat posed by antibiotics. In 2005, biochemist Floyd Romesberg of the Scripps Research Institute, near San Diego, announced that his lab had discovered a gene called LexA that switches on the error-prone DNA, enabling the microbe to mutate rapidly.
Now Romesberg has announced the discovery of a molecule that inhibits LexA’sability to cause mutations; it was found after the lab screened more than 100,000 possible compounds. The molecule also slips easily into a bacterial cell, which is critical to creating an effective tool to zap the bugs.