Even some euro bank notes may need a good scrubbing. Like dollar bills, these notes are made from cotton and they harbor an array of bacteria. hide caption itoggle caption Thomas Leuthard/The Preiser Project/Flickr Shots - Health News Dirty Money: A Microbial Jungle Thrives In Your Wallet A look at the critters that live on money finds about 3,000 types of bacteria. Most are harmless. But researchers found traces of DNA from anthrax and drug-resistant pathogens, too.