The experiments were performed in bacteria with mutations disabling some forms of DNA repair, Clauson says.
"This situation may resemble one where something like radiation or a mutagenic chemical has overwhelmed the normal repair mechanisms," she says.
In addition, Clauson used an antibiotic called novobiocin to shut down DNA replication in the bacteria. She says this simulates a more challenging environment when cells are not growing quickly.
"Our ability to see transcriptional mutagenesis in growth-limiting conditions is important," Doetsch says. "Out in the environment, bacteria are not constantly surrounded by the rich mix of nutrients we give them in the lab."
"Because this work hints at a simple mechanism by which bacteria could escape from growth-restricted environments, it has important implications for how pathogenic microorganisms may acquire resistance to antibiotics," he adds. The next phase of these studies for Doetsch and colleagues will be to test whether transcriptional mutagenesis can lead directly to antibiotic resistance in bacteria and other microorganisms.
|Contact: Vince Dollard|