Characterization of mechanisms involved in rickettsia pathogenicity

摘要: Rickettsiae are characterized by their strictly intracellular location, as Gram-negative bacteria growing only within the eukaryotic host cell cytoplasm. Accordingly, molecular mechanisms responsible for invasive largely unknown. Adhesion is a key step bacterial invasion of tissues and involves rickettsial outer membrane proteins rOmpA rOmpB, known long time major surface antigens. The aim this thesis was to gain better understanding another newly identified adhesin from Rickettsia prowazekii, called Adr2. This task achieved through production monoclonal antibody (mAb) specific recombinant protein that allowed localization Adr2 at surface. inhibition rickettsiae-induced cytotoxicity with mAb confirmed role in process. Considering putative actin-based motility pathogenesis spotted fever group rickettsiae (SFG), we then focused our second part work on RickA, SFG thought be motility. Immunofluorescence assay combined immunogold electron microscopy yielded good-resolution images showed non-polarized expression RickA found onto entire conorii. Finally, twenty targets were screened sera patients infected various rickettsiae. We thus evidenced several putaive markers allowing discriminate infection caused either typhi or On overall, believe results improve knowledge about pathogenicity genus.