Listeria monocytogenes possesses adhesins for fibronectin

Listeria monocytogenes is a gram-positive, nonsporulating, food-borne patho gen of humans and animals that is able to invade many eukaryotic cells. Sev eral listerial surface components have been reported to interact with eukar yotic cell receptors, but the complete mechanism by which the bacteria inte ract with all of these cell types remains largely unknown. In this work, we found that L. monocytogenes binds to human fibronectin, a 450,000-Da dimer ic glycoprotein found in body fluids, on the surface of cells and in an ins oluble component of the extracellular matric:. The binding of fibronectin t o L. monocytogenes was found to be saturable and dependent on proteinaceous receptors. Five fibronectin-binding proteins of 55.3, 48.6, 46.7, 42.4, an d 26.8 kDa were identified. The 55.3-kDa protein was proved to be present a t the bacterial cell surface, The binding oft. monocytogenes to fibronectin adds to the number of molecules to which the bacterium is able to adhere a nd emphasizes the complexity of host-pathogen interactions.