Figure 5. Effector translocation is dependent on C. burnetii transcription.

Inhibition of bacterial RNA synthesis through the addition of rifampicin blocks the capacity of C. burnetii to translocate BlaM-effector reporter proteins. No translocation of BlaM-77, BlaM-1823 or BlaM-1524 is detected after a 24 h infection in the presence of 10 μg/ml rifampicin (A). HeLa cells were infected with C. burnetii pBlaM-77 at an MOI of 100 and rifampicin was added at the time of infection, 2, 6, 8, 16 and 20 hours post-infection (h pi) before translocation was measured at 24 h pi (B). Translocation of the BlaM-CBU0077 fusion protein was determined by measuring the change in the 460 nm/535 nm fluorescence emission ratio resulting from cleavage of the CCF4-AM substrate (y-axis). Results represent the mean ± SD obtained from triplicate samples of a representative experiment.