FIG 5.

Intimin-like genes play a role in host bladder cell interactions in vitro but not with kidney cells. UPEC host cell association was determined in both T24 bladder (A) and HK2 kidney (B) cell lines. UPEC was added to cells at an MOI of 1:50 and incubated for 1 h before enumeration of the attached CFU. Data are the mean of five biological replicates; all data are normalized to WT adherence. Error bars represent the SEM. (C and D) UPEC cell internalization was determined in both T24 bladder (C) and HK2 kidney (D) cell lines. After 1 h of coculture of bacteria with host cells, the media were supplemented with gentamicin to kill extracellular bacteria. Bars represent the mean of internalized UPEC CFU burden from five biological replicates, with the SEM shown. (E and F) UPEC host cell-killing ability was determined in both T24 bladder (E) and HK2 kidney (F) cell lines. UPEC was cocultured with host cells for 5 h before determination of the number of UPEC CFU from cell supernatants and host viability as measured by the MTT assay. The left y axis plots the mean cell viability as determined by A₅₇₀ values via MTT, normalized to RPMI 1640 only as an internal control (black bars). The right y axis plots mean CFU/mL as determined by the collected cell supernatants (gray bars). Both data sets display the SEM. If significant, P values determined by one-way ANOVA with Dunnett’s multiple-comparison test, compared to WT CFT073, are indicated (*, P < 0.05; **, P < 0.01; ****, P < 0.0001).