I'm not a total barefooter but whenever i'm walking some place it like to slip my sandal in my bag and keep on walking but i work at a preschool and i knwo what goes down on that floor and id ont exactly wanna get intimate with it. cna nay one say anything re assuring
First of all, bacteria are nothing to be afraid of: most of them are useful to humans, and the bad ones need a door (a cut or an abrasion) to enter the body and harm it. Second, the hands, who are in contact with unknown stuff, like in the subway or the bus; grocery stores' carts, etc...are far more dirtier and disgusting than bare feet. Do you know how much germs lurk on doorknobs? You just don't wanna know... I hope it reassure you...
In my opinion, it's always better to be barefoot outdoors rather than indoors. Yeah, who knows what's lurking all over that preschool. Kids love to spread germs - but I don't know that the floor would be any worse than any other surface. If it were me, I'd wash my hands regularly at work and if barefoot, I'd scrub my feet before playing with my toes.. haha...