There has been a surge in the number of emerging zoonotic vector-borne diseases world-wide. Current research on vector-borne diseases is often focused on interactions between mammalian hosts and pathogens. Relatively little is known of the interactions that take place when pathogens are ingested by vector species. The aim of this project is to develop techniques which would allow us to track zoonotic bacteria within the vector and to identify possible interactions. Two models were used in this study: Bartonella henselae and the flea Ctenocephalides felis, and Anaplasma phagocytophilum and the tick Ixodes ricinus.