Human epithelial cells infected with E. coli

Human HeLa cells infected with Shiga toxin-producing Escherichia coli (also known as STEC, VTEC or EHEC). This strain, O157:H7, is the most prominent serotype to cause outbreaks in the UK. Bacteria and cell nuclei are stained blue, Shiga toxin is stained red, and actin green. Some cells show attached bacteria with the characteristic actin accumulation underneath.