Figure 1
Detection of C. pneumoniae in HEp-2 cells and monocytes using immunofluorescence microscopy and RT-PCR. A) C. pneumoniae (green) was detected in HEp-2 cells (upper panel) and in adherent monocytes (middle panel) at 48 h post infection. Recovery of C. pneumoniae was evaluated by recultivating disrupted monocytes at 48 h post infection in HEp-2 cells (lower panel). Cells were counterstained with Evans Blue (red), and DNA was visualized with DAPI (blue). Chlamydial inclusions are clearly demarcated in HEp-2 cells, but appear diffuse in monocytes (scale bar = 10 μm). B) Monocyte infection was performed using 2 × 104 IFU (open bars) and 2 × 103 IFU (hatched bars) per 2 × 105 monocytes, respectively, and monocyte infection rates were determined by immunofluorescence. C) C. pneumoniae 16S rDNA copies in monocytes and D) HEp-2 cells infected with 2 × 104 IFU (open bars), 2 × 103 IFU (hatched bars) and uninfected cells (grey bars) were quantified at 6 and 48 h post infection by RT-PCR. Concentrations are expressed as mean ± SD for 3 independent experiments. *P ≤ 0.05