Brucella abortus efp gene is required for an efficient internalization in HeLa cells

► We identify and characterize the Brucella abortus efp gene. ► The efp gene of B. abortus and Agrobacterium tumefaciens chvH gene are functionally homologous. ► An efp mutant grows slower in complex media and show more sensitivity to detergents. ► B. abortus efp mutant have reduced invasiveness in HeLa cells. ► efp is involved in the internalization of Brucella in non-professional phagocytes.