Fig 6.

LtpD enhances the replication of L. pneumophila 130b in THP-1 macrophages. (A) THP-1 macrophages were infected with the L. pneumophila WT, ΔdotA strain, ΔltpD strain, or ΔltpD strain expressing 4HA-LtpD (ΔltpD/p4HA-LtpD), and bacterial CFU at set time points were quantified by plating. The ΔdotA strain did not replicate. From 24 h p.i., the ΔltpD strain showed a small but significant growth defect compared to the WT strain. This growth defect could be complemented by the addition of p4HA-LtpD. The results are means of at least three separate experiments ± the standard deviations. Significance was calculated by using an unpaired Student t test.