FIG 4.

tc0437 and tc0439 mutants have reduced cytotoxicity. (A) HeLa cells were infected at an MOI of 250 in the presence of rifampin and were fixed 3 h p.i. Cell morphology and actin structure were visualized by staining with Alexa Fluor 488-phalloidin (green) and DAPI (blue). Overlays of fluorescence micrographs of cells that were mock infected or infected with C. muridarum (CM), C. trachomatis (CTL), tc0437, tc0438, or tc0439 are depicted. The images are representative of the results of three independent experiments. (B) LDH in supernatants of HeLa cells infected at various MOI in the presence of rifampin. Shown are C. muridarum (black), C. trachomatis (gray), tc0437 (hatched), tc0438 (white), and tc0439 (crosshatched). Triton X-100-treated cells were used as positive controls for LDH release. The data show the mean percentages (+SD) of the positive control from three independent experiments performed in triplicate. ****, P < 0.0001; **, P < 0.01 by one-way ANOVA with Dunnett's post hoc test.