Influenza infection (flu) is a major cause of death around the world, especially during years of flu pandemics. People who die of the flu often have a secondary lung infection with Staphylococcus aureus (staph) bacteria that starts a few days after flu infection begins. In this new research, experts from Mount Sinai studied how the flu paves the way for staph infection in the lungs. Using mouse models, the researchers found that healthy lungs secrete liquid into their air sacs that prevents a staph infection. The flu blocks this liquid secretion by inhibiting a protein called CFTR, making it possible for staph that are inhaled into the air sacs to stick to the air sac walls, initiate infection, and damage the lungs. Treatment with a CFTR-activating drug, such as ivacaftor, restores liquid secretion in air sacs of the flu-infected lungs and restores the air sacs’ natural protection against staph infection.
