Fig 1.

Intracellular replication of several L. pneumophila environmental isolates in A/J mouse macrophages. Bone marrow-derived macrophages were challenged with indicated bacterial strains grown to post-exponential phase at an MOI of 0.05. Infections were synchronized 2 h after adding the bacteria. At the indicated time points, total bacterial counts (CFU) were determined by plating appropriately diluted saponin-solubilized infected cells onto bacteriological medium. Infections were performed in triplicate, and the data shown were from one representative experiment of three independent experiments with similar results.