Bacteria and Parasites - Role of Fibronectin

The adherence of microorganisms to host tissues is often facilitated by proteins on their surface that recognize specific cell-surface receptors or extracellular matrix proteins including collagen, fibrinogen and fibronectin [ref]. The latter two proteins are present in soluble form in the blood where they might serve a protective effect as opsonins, coating certain organisms that get into the circulation and helping to mediate their clearance. However these same proteins are also present at sites of injury , most likely in aggregated form, where they may provide sites for the organisms to attach and colonize.