The Silverline series of catheters is laced with less than 1% of small silver particles and an unsoluble silver salt. Even if silver ions influence a resistance to silver, antibiotic therapy is still possible, as the ions are strong antiseptics with a wid spectrum. A large specific surface on the small particles allows for the release of silver ions on the surface of a catheter. As soon as the silver salt is placed on the catheter, ions in antiseptic concentration are released. The particles themselves start releasing ions several hours later, when the ion release from the salt begin to slow down. The process then continues over a long period of time. Silver inactivates the enzyme systems with SH-groups of the cell wall that have an active role in the transmembraneous energy metabolism.