FIG. 7.

virD4 mutation attenuates bacterial invasion. (A) Caco-2 cells were infected with C. fetus subsp. venerealis 84-112 harboring the vector control (left) (V81[pRYSS1]), the isogenic virD4 mutant harboring the vector control (middle) (V81_SK1[pRYSS1]), or the mutant strain harboring virD4 in trans (right) (V81_SK1[pRYVL2]). Extracellular bacteria were killed with gentamicin after 5 h, and the relative number of intracellular bacteria per Caco-2 cell was compared to that of the wild type (WT) (set to 100%). (B) For a negative control of the invasion phenotype, Caco-2 cells were infected with wild-type C. fetus subsp. venerealis 84-112 (V81) or the isogenic mutant in cdtB (V81_JL1) for 3 h. The values shown are the means of three independent experiments plus standard deviations; *, P < 0.02.