So just what is e.coli anyway?
Bacteria is everywhere, and actually that's a good thing.. they are
involved in biodegrading, recycling and also pumping out some very
important products like antibiotics and enzymes, and now they are saving
the lives of mice and monkeys all over the world by letting their
genetic machinery be used in place of theirs. When we say bacteria is
everywhere, we really mean everywhere. There are literally thousands
living, growing and replicating on us, and almost all of them are
working for us. The most well known of which are those in our stomachs,
helping us digest our food.
The problem is when we get infected with bacteria
that are not native to us, our digestive systems work in harmony with
"coliform" bacteria, but if any outsiders get in they start a war that
leads us to the bathrooms.. and sometimes the hospital.

e.coli under the electron microscope