What is the most common cause of infection in vascular grafts?

The most common cause of infection in vascular grafts is Staphylococcus epidermidis. This organism is part of the normal flora of human skin and is a coagulase-negative staphylococcus, which makes it well-adapted to colonize medical devices, such as vascular grafts.

Infections associated with vascular grafts often arise from bacteria that are introduced during the surgical procedure or from the skin flora of the patient. Staphylococcus epidermidis is particularly problematic due to its ability to form biofilms on foreign materials, which protects it from both the host immune response and antibiotics. This biofilm development is a critical factor in the persistence and difficulty of eradicating infections related to implanted devices.

While other pathogens, like Staphylococcus aureus and Escherichia coli, can certainly cause infections in certain contexts, they are not the most frequently implicated organisms in vascular graft infections. Staphylococcus aureus, being a more aggressive pathogen, is more commonly associated with acute infections rather than the chronic, indolent infections typically seen with vascular grafts. Thus, understanding the role of Staphylococcus epidermidis in these scenarios is essential for effective management and prevention of graft infections.