The morphology of Escherichia coli ATCC 25922 Staphylococcus aureus ATCC29213 were investigated by transmission electron microscopy. a-b The control group. c-d The Escherichia coli ATCC 25922 treated with CHAP. Most of the bacteria were translucent and pores were evident on walls especially at the two terminals of each cell (arrowheads). There was some intracellular substance released from many bacteria (arrows).