Hey germaphobes–you might want to skip this one. Via Robot Wisdom, here’s a Reuters article discussing the nastiest bits of our world:
Shopping cart handles led the way with 1,100 colony forming units of bacteria per 10 sq cm (1.55 sq inches) followed by a mouse used on computers in Internet cafes, which had an average of 690 colony forming units.
The other germy leaders are hand straps on buses and subways, bathroom doorknobs and elevator buttons.
DarrenBarefoot.com 
I hate bad science writers! Why can’t they describe what “colony forming units” are for the general populace? I have the benefit of having a MSc in microbiology, so I had no problems reading the article, but come on, even a scientist can write a better article (and that’s not saying much given that most scientists don’t need university english past first year to graduate).
Also, 1130 colony forming units is nothing. A colony forming unit is basically a bacterium that has been put onto a petri plate to grow, that clonally divides to form a colony that is visible to the eye. Therefore, the number of colony forming units is directly proportional to the number of bacteria in the original sample. Ok, if you are still reading, the point is that 1100 bacteria = nothing if not given in context. Did you know that you have more bacteria ON YOUR BODY than you have CELLS IN YOUR BODY in terms of numbers? Besides, they make no mention of what bacteria were present. I’d bet money that it was most S. epidermidis, which given the name, is commonly found on your body anyways. It will not kill you or even make you remotely ill. However, if it was S. aureus and you were immunocompromised (i.e. after a bone marrow transplant), you might get sick. But you’d probably be in the hospital anyways, not pushing a grocery cart.
Basic microbiology labs do similar testing all the time – door handles are commonly the worst.
But you know, one really has to keep it ALL in PERSPECTIVE. Your immune system is a beautiful organized system, capable of encountering and reacting promptly to 99% of infections without you ever having the realization you had even come into contact with something. It is far more powerful than most people realize, and for the grand majority (only excepting the dying and the immunocompromised), your immmune system will protect you from anything…so go ahead, lick that shopping cart handle! Ok well, don’t bother with that, but please realize that people DO NOT need to carry Purell around with them and spray antibiotic cleaners everywhere.
Oh, that’s a whole ‘nother rant. I’ll stop here.
need to settle a bet with my husband. what part of the body houses the most germs
IF you wipe off shopping cart handles you shouldn’t have a real problem with getting sick. Also if someone coughs you can hold your breath until you get to a safer location to breath. I swear by AIRBORNE – you get them at the grocery store. Then I take four capsules of olive leaf extract. That stops the germs from taking up residence in my body. I also drink teas with hyssop in them. So you can’t stay away from germs permanently but you can make them feel less at home in your body.