FIG. 2.

Relative transcription of SPI-1 (sipC) and SPI-2 (sseC) genes of S. enterica serovar Typhimurium F98 within amoebic cells 1 and 4 h postinfection. Salmonella was added to the amoebae at an MOI of 10. Changes in expression were determined by real-time quantitative RT-PCR compared to transcription of bacteria grown in LB broth and using the housekeeping gene yejA as an internal standard. Data shown are the mean values for the change in expression ± standard errors of the means (error bars) from eight replicate experiments.