FIG 4.

Uptake of H. ducreyi by and survival within human macrophages. (A) Percent uptake of 35000HP strain and 35000HPΔdksA mutant strain by human monocyte-derived macrophages (MDMs). MDMs were infected with opsonized H. ducreyi at an MOI of 10:1. The percent uptake was calculated as follows: (geometric mean CFU of gentamicin-protected bacteria at 1 h/geometric mean CFU of input bacteria) × 100. (B) Percent survival of 35000HP strain and 35000HPΔdksA mutant by MDMs. To determine survival, the MDMs were incubated an additional 5 h, and bacteria were collected. Survival was calculated as follows: (geometric mean CFU of bacteria collected at endpoint/geometric mean CFU of gentamicin-protected bacteria at 1 h) × 100]. Data are mean ± SD from 5 independent donors. Values that are significantly different (P ≤ 0.05) are indicated by a bar and asterisk.