Figure 2.

Cytotoxic effect of L. pneumophila on A549 cells. A549 cells were infected with L. pneumophila virulent AA100jm and avirulent dotO mutant strains. LDH levels in the cell supernatants showed a time-dependent change after infection with L. pneumophila at an MOI of 20 (A), and an MOI dose-response relationship 2 days after infection (B). Symbols : ▫, virulent strain AA100jm; ▪, avirulent strain dotO mutant. Data are mean ± SD of three wells. * P < 0.05.