In the present study, we used single-molecule AFM techniques to study the nanomechanical properties of the interactive forces between VE-cadherin and living human cerebral microvascular endothelial cells upon infection with R. montanensis, which is genetically similar to R. rickettsii and R. conorii and displays a similar ability to invade cells in vitro and can be experimentally manipulated in the Biosafety Level 2 (BSL2) environment [1], [2], [31]. Here, CDH5 is linked to infection.