How Bacteria Evolve Into Superbugs
Researchers have applied ecological and evolutionary theory to demonstrate how bacteria become resistant to antibiotics in hospitals.
Their study shows how high rates of immigration of bacteria into an environment containing antibiotics introduces sufficient genetic variation to cause the evolution of antibiotic resistance, a finding that sheds light on the growing incidence of highly antibiotic-resistant "superbug" bacteria such as Pseudomonas aeruginosa.
"Bacteria that can mutate fast will quickly adapt to harsh environments containing antibiotics. Our study showed that a high rate of immigration significantly augments the regular process of genetic mutation commonly used to explain the evolution of antibiotic resistance," said co-author Dr. Andrew Gonzalez, a Canada Research Chair in Biodiversity and associate professor in the Department of Biology at McGill. Gonzalez explained that the flow of bacteria in the experiment is analogous to the immigration of bacteria-carrying individuals into a hospital, and "the rate at which bacteria are entering a particular environment