For a healthy individual, the likelihood of actually getting a disease from a toilet seat is pretty small. Your skin has a lot of barriers against things from the outside, and is pretty good at keeping out bacteria. If you had some sort of infection or rash already, you could probably get a staph infection or something like that, but you would have to already have some sort of break in the skin for that to happen. I don’t want to say it’s impossible—it’s possible—but I think the likelihood that any given sit on a toilet seat will result in an infection is probably very small.
I could see if you had a very dirty toilet seat, you could potentially get a staph infection, and there are staph infections nowadays that are resistant to antibiotics. But those tend to be found in hospitals, not in the wild.
The only cases I’ve read [involving someone getting a disease from a toilet seat] were contact-dermatitis type things, and that’s usually in children, where they’re having some sort of allergic reaction or diaper rash that gets irritated by either the plastic or the cleaning fluid that’s used. But that’s also not particularly common, and people grow out of it pretty quickly. At least in the case studies, I haven’t’ seen any instance of somebody contacting [an infection] from a toilet seat, and that is the type of thing that somebody would write up as a case report. I’d take the lack of evidence there asevidence of it not really happening.