Minimization of the Legionella pneumophila genome reveals chromosomal regions involved in host range expansion.

ABSTRACT: Legionella pneumophila is a bacterial pathogen of amoebae and humans. Intracellular growth requires a type IVB secretion system that translocates at least 200 different proteins into host cells. To distinguish between proteins necessary for growth in culture and those specifically required for intracellular replication, a screen was performed to identify genes necessary for optimal growth in nutrient-rich medium. Mapping of these genes revealed that the L. pneumophila chromosome has a modular architecture consisting of several large genomic islands that are dispensable for growth in bacteriological culture. Strains lacking six of these regions, and thus 18.5% of the genome, were viable but required secondary point mutations for optimal growth. The simultaneous deletion of five of these gen

SUBMITTER: O'Connor TJ 

PROVIDER: S-EPMC3169125 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature