New research led by Sarah Danchuk, PhD, and Marcel Behr, MD, M.Sc., at the Research Institute of the McGill University Health Centre (The Institute) reveals for the first time that some animal strains of the bacteria causing tuberculosis (TB) are significantly more virulent than their human counterparts. Published in the journal PNAS, the study challenges a long-standing assumption that members of the Mycobacterium tuberculosis complex have the same infection outcome, regardless of the host they infect, and redefines assumptions about TB evolution and pathogenesis.
“Despite sharing over 99.9 percent of their genetic code, these bacteria don’t behave the same way in infection,” said Dr. Behr, principal author of the study and senior scientist in the Infectious Diseases and Immunity in Global Health (IDIGH) Program at The Institute. “Our findings show that animal-adapted strains can cause dramatically more severe disease than the human strain, underscoring the need to follow the One Health approach and study both the pathogen and its hosts together.”