FIGURE 3.

The Δstp1 mutant is attenuated for its ability to induce an inflammatory response (A) and decrease barrier integrity (B) of hBMEC. A, qRT-PCR was performed on RNA isolated from hBMEC cells infected with either WT A909 or the Δstp1 strain. Note that transcription of IL-6, IL-8, and CCL20 was significantly decreased in hBMEC that were infected with the Δstp1 mutant compared with the WT A909 (p < 0.005). Error bars, S.E. B, time-dependent decrease in hBMEC resistance due to infection with Δstp1 was compared with WT, ΔcovR, ΔcylE, and ΔcovRΔstp1. Resistance was assessed by ECIS and is normalized to the uninfected or medium-only control.