Which is why many door knobs are made from brass. It kind of self disinfects itself.
You'd have to, like, touch the bacteria and then put it in your mouth, nose or eyeball... or something. So, if you're rubbing your hands all over chairs that other people who have poo on their pants just sat in, you could be in for some trouble.
So you can't take anything to the toilet with you? What about clothes?
I believe the worst place in a public bathroom is actually the door knob. Everyone touches it, most of those w/o having washed their hands. So you wash your hands, think you're squeaky clean, then touch that door knob and get poo on you.