This is a colorized transmission electron micrograph of Escherichia coli O157:H7 showing flagella. Pseudoreplica technique. E. coli O157:H7 was first recognized as a cause of illness in 1982 during an outbreak of severe bloody diarrhea; the outbreak was traced to contaminated hamburgers. Since then, most infections have come from eating undercooked ground beef.
E. coli bacteria, SEM Caption: E. coli bacteria. Coloured scanning electron micrograph (SEM) of Entero Pathogenic Escherichia Coli (EPEC) bacteria (red) attached to the surface of a human epithelial cell (green). The bacteria have induced the cytoskeleton of the host cell to form 'pedestals' on which the bacteria are sitting. EPEC is a pathogenic variety of a common gut bacteria.