The salad drawers are the most infested with bacteria.
The fridge salad draw having seven hundred and fifty level of bacteria is considered to be safe, but recent discovery of killer bugs like E.coli, salmonella and listeria are found and add an average of seven thousand eight hundred and fifty a level bacteria which is per square centimetre. The swabs that were tested had as much as one hundred and twenty nine thousand square centimetre.
The bacteria multiply in warmer weather, the low temperatures in the fridge only inhibits the growth of the bacteria, and with regular cleaning is the answer of keeping it safer.
Regular cleaning of the salad draws should be done separately, the problem occurs if your drawers are never cleaned.
It comes as a surprise when you think of it, the whole purpose of the fridge is to keep food safe and control the chances of bacteria growth, this is a problem.