FIG. 3.

Individual SPI1-associated mutants that constitutively produce light were assayed for replication defects in RAW 264.7 macrophage cells as described in the legend of Fig. 2. Each strain was tested in quadruplicate, and the average log₁₀ relative light units (RLU) are reported after normalization to wild-type SL1344 levels and levels at 3 h postinfection. The ssrAB strain was included as a control. These results are representative of multiple assays. “p” indicates polar mutants, while “np” indicates nonpolar mutants. Standard errors are reported, and asterisks indicate significance (P < 0.01) as calculated using an unpaired t test comparing each mutant to the wild-type strain for each respective time point. Hours postinfection are indicated, and none of the strains displayed a growth defect in LB.