FIG 5.

Role of virulence factors in human placenta. Primary human placental organ cultures were infected with a 1:1 ratio of WT (erythromycin resistant) and WT (erythromycin susceptible) or the following mutant strains (all erythromycin susceptible): ΔinlP, ΔinlP mutant complemented with inlP, ΔinlA, Δhly, ΔplcAB, and ΔactA. The ratio of erythromycin-resistant to erythromycin-susceptible CFU was determined at 6 h p.i. (A), 24 h p.i. (B), and 72 h p.i. (C). Mann-Whitney U test was used for statistical analysis (*, P < 0.05; **, P < 0.005; ***, P < 0.001; ****, P < 0.0001). Horizontal bars indicate medians.