FIG. 5.

Effect of altered OAg length on phagocytosis and intracellular replication of S. enterica serovar Typhimurium. RAW macrophages were infected at an MOI of 1 with WT S. enterica serovar Typhimurium, a strain deficient in the SPI2-T3SS (ssaV), or various mutant strains deficient in OAg biosynthesis. (A) For quantification of phagocytosis, the CFU of intracellular bacteria was determined 2 h after infection, and relative uptake was expressed as a percentage of the inoculum. (B) For quantification of intracellular replication, infected cells were lysed 2 h and 16 h after infection, and the CFU of intracellular bacteria was quantified. The x-fold change in intracellular replication is the ratio of CFU recovered at 16 h versus that recovered 2 h after infection. Means and standard deviations for triplicate assays are shown. Statistical analysis was performed as described in the legend for Fig. 2.