FIG. 2.

Cytopathogenicity of GK11 and AA100 to U937 macrophage-like cells (A) and WI-26 alveolar epithelial cells (B) as determined by Alamar blue dye staining. K9 is a cosmid-complemented clone of GK11. Percent survival of cells was normalized to uninfected cells, which were considered 100% viable. Experiments were performed in triplicate and repeated at least three times. The data are from a representative experiment. Error bars represent standard deviation of the mean. ∗, significantly fewer intracellular bacteria than in wild-type (AA100)-infected cells, based on Student's t test (P < 0.05).