Great question! You could actually do this kind of survey yourself for a great science project! You can google "kitchen bacteria" and get some great info links about how to test your own kitchen and bathroom. Lots of people think about this and work on it.

Our world is full of bacteria and viruses, and for the most part, we never notice them - unless they make us sick. A common "swipe" through a reasonably clean kitchen and bathroom will yield millions of bacteria of many types - very few harmful. However, if you work with food products and then fail to clean up, watch out! Most vegetable have bacteria on them - and they are tough to wash off. Not a big deal unless (1) the veggies are starting to rot/decay or (2) the veggies were harvested or processed in such a way that came into direct contact with human or animal waste. Then, they can carry a harmful form of E. coli bacteria (there are many strains of E. coli, most are harmless, some are helpful, but a few are bad news). If the bacteria get on a kitchen surface like a counter top or cutting board, or especially a warm, moist, dish rag or sponge, they can start multiplying and the chance of contaminating other foods or a person directly increases. The same holds true for bacteria associated with meats. Raw chicken especially often carries a form of Salmonella bacteria, which can cause food poisoning, but any meat should be handled with care and clean up should be fast and complete. And avoid using the same space and utensils for meat and vegetables - keep them separate! Now, you also asked about bathrooms. Again, you might be surprised to know that there are lots of bacteria, but not usually harmful. Here is a link to a really cool website that explains this (and a ton of other really interesting stuff - kind of like the show "MythBusters"):

Kitchen science

Have fun looking deeper into this great question!