FIG. 7.

Intracellular infection of murine alveolar macrophages by wild-type and lbtA mutant L. pneumophila. Explanted alveolar macrophages from A/J mice were infected with wild-type strain 130b (▪) and lbtA mutant NU302 (○), and then at various time points, the CFU in infected monolayers were determined by plating. Data are the means and standard deviations (error bars) obtained from four infected wells. No significant differences were obtained between the CFU recovered from cells infected with the wild type and those infected with the mutants at 0, 24, 48, and 72 h postinoculation (Student's t test, P > 0.05). The results presented are representative of two independent experiments.