Fig. 8.

Intracellular and intrapulmonary growth of the L. pneumophila wild type and bbcB and bbcI mutants. (A to E) H. vermiformis (A), A. castellanii (B), U937 macrophages (C), A549 type II epithelial cells (D), and WI-26 type I epithelial cells (E) were infected with WT 130b (▪), bbcB mutant NU388 (□), and bbcI mutant NU389 (▴), and then at the indicated times, the numbers of CFU in the infected monolayers were determined by plating. Data are the means and standard deviations for four infected wells. Each panel is representative of three independent experiments. (F) WT 130b (▪) and bbcI mutant NU389 (▴) were inoculated into the lungs of A/J mice, and then after 24, 48, and 72 h, the numbers of CFU in total lung homogenates were determined by plating. Data are the means and standard deviations for five infected animals. While there might appear to be no growth and reduced recovery of the mutant at 24 h, this result was not statistically significant and was not obtained in the repeat experiment (data not shown).