OMVs are nanoscale spherical bilayer-membrane vesicles naturally secreted during the growth of E. coli that retain outer membrane and periplasmic components similar to those of the source bacteria. The FimH-positive E. coli can enter macrophages through caveolin-mediated endocytosis, which enables them to bypass lysosome processing and to maintain a stable nanostructure. We performed proteomic analyses on the OMVs.