The invention relates to a Rho GTPase activator, such as namely the cytotoxic necrotizing factor 1 (CNF1), for use in preventing and/or treating infections by a pathogen in a patient in need thereof. The invention also relates to a Rho GTPase activator, such as CNF1, for use in preventing and/or treating pathologies associated with an infection by a pathogen in a patient in need thereof. For instance, the invention relates to a Rho GTPase activator for use in treating infections by bacteria in a patient in need thereof and also relates to a Rho GTPase activator for use in reducing or eliminating bacteremia in a patient in need thereof.