New research suggests that some patients develop a potentially deadly blood infection from their implanted cardiac devices because bacterial cells in their bodies have gene mutations that allow them to stick to the devices. Patients with implants can develop infections because of a biofilm of persistent bacterial bugs on the surfaces of their devices. Researchers found that some strains of the bacteria, Staphylococcus aureus, have just a few genetic variants in the proteins on their surfaces that make them more likely to form these biofilms.