Researchers at Michael G. DeGroote Institute for Infectious Disease Research, have delved into how diseases evolve, for instance the manner in which bacteria adopts new forms.
The finding can help scientists identify and assign risk to emerging diseases in the environment.
It was found that bacteria could develop into illness-causing pathogens by rewiring regulatory DNA, the genetic material that controls disease-causing genes in a body.
Earlier, it was believed that disease evolution occurs mainly through the addition or deletion of genes.
But the study led by Brian Coombes, an assistant professor in the Department of Biochemistry and Biomedical Sciences, along with researchers at McMaster University, the University of Melbourne, Australia, and the University of Illinois at Chicago, USA, has challenged that thinking.
"Bacterial cells contain about 5,000 different genes, but only a fraction of them are used at any given time. 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," Coombes said.
He added: "We've discovered how bacteria evolve to turn on just the right combination of genes in order to cause disease in a host. It's similar to playing a musical instrument - you have to play the right keys in the right order to make music
As there's a rise in infectious diseases, the finding has implications on how new pathogens are identified in the environment.
Currently, scientists monitor the risk of new diseases 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. Because now, we know it's not just gene content - it is gene content plus regulation of those genes," said Coombes.
The study has been published in the journal Proceedings of the National Academy of Sciences.