FIG. 10.

Intracellular growth rate of wild-type F. tularensis and ΔpyrF mutants. Mean generation time (± SEM) was calculated for bacterial replication in primary human macrophages, HEK-293 cells, or NHDF cells from at least three combined independent experiments. Panel A shows the mean generation time comparison of LVS and LVS ΔpyrF, and panel B depicts the Schu S4 and Schu S4 ΔpyrF data. For both panels, the generation time of the ΔpyrF strains in macrophages could not be calculated, because the mean numbers of viable CFU across experiments were lower at 24 h than at 2 h postinfection (asterisk).