FIG 6.

Prolonged exposure of HCLE cells to supernatants of K904 and protease mutants suggest a role for SlpB in cytotoxocity to ocular cells. Cytotoxicity of normalized bacterial supernatants to HCLE cells was measured using Presto blue (n = 3). These experiments were done without a washing step so that detached HCLE cells were included in the assay. Means and standard deviations are shown. The asterisk indicates statistical difference from K904 by ANOVA with Tukey's posttest. Pound signs indicate a significant difference between K904 prtS and K904 prtS slpB by ANOVA with Tukey's posttest. (A) 4-h exposure; (B) 24-h exposure.