Shigella infection

Human intestinal cells infected with Shigella, an enteroinvasive strain of E. coli a common cause of dysentary. The cell nuclei are stained red and the cytoskeletal actin green. Once released into the cytoplasm, the bacteria multiply and nucleate host cell actin on one end. This hijacking of cellular protein confers motility to the bacteria (blue) and can be observed as a characteristic “comet tail” (green).