Certain infectious agents reach the blood during infection, in most cases this step is a sign of extreme severity of the disease. Colonization of the blood can have different types of pathological consequences for the vascular system. Our goal is to decipher the molecular and cellular basis underlying these pathological effects, both on the side of the microorganism and on the host side.

 • Vascular leak: In this case infection affects the junctions between the endothelial cells leading to hemorrhagic syndromes (Ebola virus or West Nile virus, Rickettsia spp. etc)

 • Septic shock:  The most severe consequence of colonization of the blood by a variety of Gram negative or positive bacteria.

 • Dissemination to other organs: In other instances, blood colonization can be the port of entry to other organs such as the brain, as for example with Neisseria meningitidis infection (Figure), leading to further complications and sequelae..

 • Endocarditis: Heart valves are the site of infection and can be progressively destroyed by pathogens leading to heart failure.

 A common denominator to these pathological processes is the colonization of the vascular wall by the pathogen. Our group is dedicated to the understanding how bacterial pathogens are able to colonize blood vessels.

To address experimentally how bacteria colonize the vessel wal the specific environment of these infections needs to be taken into consideration. Blood vessels are complex multicellular structures with a specific architecture. The bloodstream generates intense mechanical forces, which affect vascular function and the infection process.