Legionellosis is a disease of significant medical and public interest. Legionella is commonly found in aquatic habitats where its ability to survive and to multiply within different protozoa equips the bacterium to be transmissible and pathogenic to humans. In addition, Legionella has become a favored model system to analyze the mechanisms of bacterial survival, acquisition of nutrients, and intracellular replication. Following the recent publication of the genome sequences of four L. pneumophila strains, it is now feasible to investigate the whole genome in silico, the transcriptome via...