A group of researchers have found that bacteria evolve into illness-causing pathogens through changes in regulatory DNA. Previously, disease evolution was thought to occur mainly through the addition or deletion of genes.
Currently, risk of new diseases is monitored by assessing the gene content of bacteria found in water, food, and animals. “This opens up significant new challenges for us as we move forward with this idea of assigning risk to new pathogens,” remarks Brian Coombes, Ph.D., assistant professor at McMaster University and lead investigator. “Because now we know it's not just gene content it is gene content plus regulation of those genes.
“Bacterial cells contain about 5,000 different genes, but only a fraction of them are used at any given time,” Dr. Coombes continues. “The difference between being able to cause disease or not cause disease lies in where, when, and what genes in this collection are turned on. We've discovered how bacteria evolve to turn on just the right combination of genes in order to cause disease in a host.”
Scientists from McMaster University were joined by investigators from the Michael G. DeGroote Institute for Infectious Disease Research, the University of Melbourne, and the University of Illinois at Chicago. Their findings were published in the February 16 issue of the Proceedings of the National Academy of Sciences.