The evolution of chronic infection strategies in the alpha-proteobacteria

Nat Rev Microbiol. 2004 Dec;2(12):933-45. doi: 10.1038/nrmicro1044.


Many of the alpha-proteobacteria establish long-term, often chronic, interactions with higher eukaryotes. These interactions range from pericellular colonization through facultative intracellular multiplication to obligate intracellular lifestyles. A common feature in this wide range of interactions is modulation of host-cell proliferation, which sometimes leads to the formation of tumour-like structures in which the bacteria can grow. Comparative genome analyses reveal genome reduction by gene loss in the intracellular alpha-proteobacterial lineages, and genome expansion by gene duplication and horizontal gene transfer in the free-living species. In this review, we discuss alpha-proteobacterial genome evolution and highlight strategies and mechanisms used by these bacteria to infect and multiply in eukaryotic cells.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Alphaproteobacteria / pathogenicity*
  • Alphaproteobacteria / physiology*
  • Animals
  • Biological Evolution
  • Chronic Disease
  • Eukaryotic Cells / microbiology
  • Genome, Bacterial*
  • Gram-Negative Bacterial Infections / microbiology
  • Humans
  • Plants / microbiology
  • Symbiosis
  • Virulence