E coli induces apoptotic-like features in platelets. (A) Platelets were incubated for 8 hours alone (left) or with E coli (EC-SP), an isolate from the bloodstream of a patient diagnosed with sepsis (middle and right). Left and middle: Confocal microscopy of polymerized actin (phalloidin, green stain) and DNA (topro 3, magenta stain) in platelets and EC-SP (E), respectively. Far right: Transmission electron micrograph of the platelet and EC-SP (E) suspension cultures. The white arrows point to lateral condensation of polymerized actin, whereas the magenta arrows (right) identify granules that have moved to one side of the cell. Scale bars = 2 μm in the left and middle, 1 μm in the right. These micrographs are representative of 3 independent experiments. (B) Mitochondrial membrane potential (ΔΨm) in platelets or EC-SP that were cultured (8 hours) alone (left and middle) or together (right). Bacteria population in middle and right panels is indicated by green box. This flow cytometric experiment is representative of 3 independent studies. The green box identifies the major population of EC-SP.
