Figure 2.

Quantitative analysis of viable intracellular C. ulcerans in THP-1 cells. THP-1 cells were infected with C. ulcerans wild type strains 809 and BR-AD22 at an MOI of 1 for 30 min. To kill extracellular bacteria, cells were incubated with medium containing gentamicin and after 2 (white bars), 8 (gray bars) and 20 h (black bars), cells were harvested, lysed and lysates were plated on blood agar plates to recover intracellular CFU. A) Intracellular CFU in percent referred to the inoculum, B) intracellular survival in percent referred to the bacteria that were taken up after 2 h. Data shown are mean values of 4 independent biological replicates each performed in triplicates ± standard deviation.