Interaction of M. suis with porcine endothelial cells induces actin condensation in vitro. Confocal laser scanning micrographs of PAECs incubated with M. suis (1 × 104 cells/mL). Cytoskeletal actin was stained with FITC-phalloidin (green); M. suis cells were stained with anti-HspA1 antiserum and TRITC-labeled secondary antibodies (red). Nuclei and bacteria were counterstained with DAPI (blue). The image represents an overlay of all fluorescent channels. (A) 90 min post-infection (pi); scale bar = 40 μm; (B) 6 hours pi; scale bar = 20 μm; (C) 4 days pi; scale bar = 10 μm; (D) Pre-infection; scale bar = 50 μm.