Common themes in symbiosis and pathogenesis: the case of Brucella abortus

摘要

Brncella spp. are intracellular pathogens that, together with Agrobacterium and Rhizobium, belong to the alpha-2-subgroup of proteobacteria. Brucella spp. invade professional and non-professional phagocytic cells through the endocytic pathway exploiting the autophagic machinery and establish a unique replication niche in the endoplasmic reticulum. No cell damage is observed upon intracellular multiplication, thus indicating that Brucella is a refined parasite well adapted to the intracellular lifestyle. In this sense, Brucella resembles an endosymbiont rather than a pathogen. The presence of several virulence genes homologous to those that in Agrobacterium or Rhizobiaceae are involved in bacterial/plant interaction, suggests common pathways for intracellular adaptation in plants and mammals.