HeLa cells (A and B) or BMDMs (C and D) were infected with O. tsutsugamushi at an MOI of 1. At 2, 4, 8, 12, or 24 h, the cells were fixed and screened with antibodies against O. tsutsugamushi TSA56 (Ot) and p65 prior to examination by confocal microscopy. (A and C) Representative fluorescence images of cells viewed for Ot, p65, and merged images plus DAPI, which stains the nucleus, are presented. White arrows denote representative individual O. tsutsugamushi bacteria. (B and D) The mean percentage + SD of cells exhibiting p65 in the nucleus was determined at each time point. Triplicate samples of 100 cells each were counted per time point. Results are representative of three separate experiments.