FIG. 6.

Induction of SPI2 in the intracellular environment. (A) RAW264.7 macrophage-like cells were infected for 4 h, and this was followed by lysis and a LacZ assay. The SPI2 and ompC promoters exhibited significantly increased activity, while ompF did not, which correlated with the presence of OmpR-P. (B) EnvZ but not acetyl phosphate is required for full expression of ssaG-gfp in the intracellular environment. The error bars indicate standard errors (n = 3), and the P values are the result of unpaired t tests assuming unequal variances.